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Patented July 23, 1929.

UNITED STATES PATENT OFFICE.

JOHN B. TERRY AND RALPH HALLORAN, OI BERKELEY, CALIFORNIA, ASSIGNORB, BY MESNE ASSIGNMENTS, '10 STANDARD OIL COMPANY OF CALIFORNIA, 01 LOS ANGELES, CALIFORNIA, A CORPORATION OF DELAWARE.

rnocnss ronraonucmo nunarcnrmo on. rnom PETROLEUM om N0 Drawing. Application filed February 14, 1928, Serial No. 619,012. Renewed Kay 16, 1928.

This invention relates to a process for producing lubricating oil and other valuable.

We have discovered that when such residual asphalt is heated to a decomposing temperature and preferably a material portion of the asphalt destructively distilled ofi that the residuum of such treatment has undergone a marked change in properties. While normally asphalt is substantially entirely soluble in light petroleum distillates, the residuum following the decomposition treatment is readily separated by light etroleum distillates into an insoluble brownis powder, and an extract of a heavy viscous lubricating oil which is substantially free of asphalt and readily refined for the production of high grade lubricating oil.

Ve have further discovered that the extract of such decomposed asphalt can be readily treated and will yield petrolatum or high melting wax, which products are normally not commercially recoverable from asphaltic base crudes.

The objects and advantages of this invention will be readily understood from the hereinafter described processwhich is given as a preferred example of a process embodying the invention. The invention is not limited to such preferred example but may be modified and embodied in numerous forms;

We prefer to charge crude oil into a still or a series of stills, and distill the crude oil until the residuum or asphalt has been reduced, as far as can be practically carried out without destructive distillation of the very high boiling products being distilled off at this point. For'this purpose high vacuum and steam should preferabl be employed during the fractionation of e high boiling point oils, so that a maximum production of uncracked high boiling viscous bodies may be obtained.

When this degree of distillation of the crude oil has been reached, further distillation will result in a distillate which contains increasing percentages of decom osedfrac-,

the usual method.

In the next stage of the process Whether the asphalt is produced by the preferred process or any other, or whether or not the asphalt is reduced to such penetration test given as an example, asphalt is distilled with an accompanying decomposition until the residuum of such asphalt is converted into substantially two constituents, i. e. viscous,

high boiling oil and a brownish powder in-- soluble in light petroleum distillates. Such distillation of the asphalt may be carried out with the aid of vacuum and steam, to assist the vaporizing of the distillate, but essentially the distillation must be conducted with a substantial cracking of distillate. The distillate throw over will be of relatively low boiling point and low viscosity, and will constitute an inferior stock for the production of lubricating oils, Such distillate may be readily used as fuel oil. g

The degree to which the distillationof the asphalt should be carried out varies with the nature of the asphalt distilled and the relative proportions desired of the fuel 011, and thereafter produced lubricating Oll. The degree of distillation of the asphalt thus var1es with choice of the refiner, but the dlstillation must be conducted until the residuum or pitch will yield with light petroleum distillates a substantially asphalt-free extract of'lubricating oil, and the distillation should not be continued until the asphalt begins to coke. We prefer to continue the distillation until the pitch in the still is still liquid at the high temperature employed, but

tration of approximately as determined by if some ten percent more of the pitch were distilled off, the residuum would then be no longer liquid, but would become a granular, coky, semi-liquid substance, which is the first stage of coking as known to the art. We refer to the pitch produced by our preferred operation as aforesaid as near coke.

When using a familiar 7O penetrationasphalt, thedistillation of approximately 50 percent of the asphalt will result. in the described pitch. The preferred pitch when drawn from the still and cooled, is of a brittle, flinty character, not sticky at normal temperatures. Such pitch is characterized by a melting point having a ball and ring test of higher-than 200 degrees Fahrenheit, and is also characterized as having'a solubility in 86 Baum gravity gasoline, as determined by the method given in Richardsons-The Modern Highway published by Wiley & Sons of not in excess of 65- percent.

The following figures illustrate an example I of an analysis of a pitch found suitable for the extraction of lubricating oil. 2

Specific gravity 1.424 Penetration n 2 Melting point 240F. Soluble:

(a) Carbon bisulphide 90.6%

(6) Carbon tetrachloride 69.48%

(a) 86 B. gasoline 52.3 Fixed carbon 27.95

Free carbon 9.38

The pitch may be produced by the preferred process. or in one single distillation from petroleum. However, produced, the pitch is mixed with a solvent oil. More efficient results may be obtained if the pitch is mixed with the solvent while still somewhat heated. The solvent oil used should be in a ratio of at least one part of solvent to two parts of pitch brownish powder which is intended to be sepbutyl, and amyl and arated. from the oil constituents of the pitch. Alcohol (methyl or ethyl) with ethyl ether or benzol, higher alcohols such as propyl, combinations of any or all such compounds, all of which may be adjusted to have about the same solvent power with regard to asphaltenes (intumescent material) as the lighter petroleum distillates,

' are examples of other solvents that may be em loyed.

,ith a pitch ofthe analysis given approximately 50 percent thereof goes into, solution with solvent oil. The solution is then filtered or otherwise separated from the insoluble portion.

The insoluble product is a brownish black powder, characterized by a high nitrogen content as compared to the crude oil, high carbon content, and by the fact that although inflammable as a powdered fuel, it does not melt but rather intumesces. Such powder is suitable for powdered or colloidal fuel, or because of its high nitrogen content valuable as fertilizer. The powder is also soluble in aromatic solvents and may be used as a paint.

. The dissolved portion of the pitch is relatively free of asphalt or pitch, and may be processed to yield a high grade viscous lubricating oil suitable as a cylinder oil. Such oil is relatively stable at high temperatures, which due to prolonged heating and the high temperatures employed in its production probably contains a material amount of polymerized bodies. Normally such extract will contain a considerable amount of petrolatuin even when employing crude 'asphaltic base oil from which hitherto it has been impossible to obtain petrolatum. Preferably such petrolatum should be extracted by one of the well known cooling processes commonly used on wax bearing crudes. The petrolatum may be further converted into paraflin wax by well knmvn processes. Thus the extractof pitch-may yield petrolatum and paraffin wax even from crudes from which such products cannot normally be obtained.

The extract of the pitch is refined to produce high grade viscous lubricating oil in a .manner similar to the, treatment of normal lubricating distillates of petroleum. lVe prefer to first treat the extract with sulphuric acid of approximately 66 Baume gravity using a half pound or more of acid to a gallon of finished oil. The acid is withdrawn from the oil and the oil neutralized with caustic soda solution, and washed with'water. The solvent isthen distilled off, leaving a high grade lubricating oil havingan exceptionally narrow range of boiling temperatures. The oil is preferably clarified by filtering through fullers earth.

The penetration values herein contained are measured, as usual, by a penetrometer, a device for measuring the distance a standard needle will vertically penetrate a sample of the material when weighted with 100 grams for five seconds at25 C. The melting point of the asphalt and other products are obtained by the ring and ball method described in the Handbook of Petroleum Asphalt and Natural Gas, and Cross Bulletin No. 17 of Kansas City testing laboratory, in which a brass ring in diameter, g deep and wall is suspended 1" above the bottom of a beaker, and \a steel ball in diameter weighing between 3.45 and 3.50 grams, a standardized thermometer, and a 600 cc. glass beaker are employed. For such tests, a sample to be tested is first. melted and the ring filled with the material, an excess being removed. After cooling, the ball is then placed in the center of the ring and suspended in the beaker containing water at a temperature of 5 C. The water-is then heated uniforml at a rate sufficient to raise the temperature the water C. per minute. Record the temperature at starting the test and every minute thereafter until the test is completed. The softening point is the temperature at which the specimen touches the bottom of the beaker. For temperatures above 99 C. glycerin should be used instead of water.

Our invention is not limited to the process described herein as an example of the preferred embodiment of the inveiition, but various modifications may be made without departing from the s irit of the invention. Our invention is oft e scope set forth in the following claims:

l/Ve claim:

1. In a process of manufacturing lubricating oil, distilling petroleum oil to asphalt while avoiding decomposition through the employment of a reduced pressure during such distillation, then destructively distilling off approximately half said asphalt to form a residual brittle, non-sticky pitch, and then extracting the lubricating oil constituents from the pitch with petroleum naphtha.

2. A process of treating asphalt consisting in distilling the asphalt to a pitch, extracting the lubricating constituents from the pitch with petroleum naphtha adapted to precipitate the resultant intumescent material, cooling the extract, thereby precipitating petro latum therefrom, separating the petrolatum' from the extract, and distilling ofi the solvent from the extract.

3. A process of treating petroleum oil to produce lubricatingoil, which consists in distilling the oil to asphalt while avoiding decomposition by employing reduced pressure during said distillation, then distilling the asphalt to a pitch and extracting the lubricating oil constituents from the pitch with.petroleum naphtha adapted to precipitate the resultant intumescent material.

4. A process of producing lubricating oil from a residual petroleum asphalt comprising destructively distilling the asphalt until a residue is.- formed of-substantially asphalt free viscous oil and intumescent material, and separating the viscous oil from intumescent material by treatin the residue with a solven of the oil whic is not a solvent of the intu escent material.

5. A process of producing lubricating oil from a residual petroleum asphalt comprising destructively distilling the asphalt until a residue is formed of substantially asphalt free viscous oil and intumescent material, separating the viscous oil from intumescent material by treating the residue with a solvent of the oil which is not a solvent of the intumescent material, and distilling the solvent from the viscousv oil. A

6. A process of producing lubricating oil from residual petroleum asphalt comprising destructively distilling the asphalt until a near coke residue is formed containin viscous oil and intumescent material, an separating the viscous oil from the intumescent material by a solvent of the viscous oil which is not a solvent of the intumescent material.

proximately one half t ereof remains as a substantially asphalt free residue of viscous oil and intumescent material, and separating the viscous oil from the intumescent material by a solvent of the viscous oil which is not a solvent of the intumescent material.

. 1 8. A process of producing lubricating oil heit and a solu ility of not more than 65 percent in 86 Baum gravity gasoline, and separating viscous oil from the'residue by a solvent of viscous oil which is not a solvent of the remaining constituents of the residue.

9. A process of producing lubricating oil from residual petroleum comprising destructively distilling the asphalt until a substantially asphalt free near coke residue is formed containing viscous oil, and separating the viscous oil from the residue by a solvent of viscous oil which is not a solvent of the remaining constituents of the residue, the solvent being used in a ratio of at .least one part of solvent to two parts of residue and not in excess of ten parts of solvent to one part of residue.

Signed at Richmond, California, this 30th day of January, 1923.

. JOHN B. TERRY.

RALPH A. HALLORAN. 

